[unreadable] [unreadable] Our research has shown that systemic lupus erythematosus (SLE), one of the most common autoimmune diseases in women, is associated with cancer. By collaborating with researchers worldwide, we have assembled the largest-ever cohort of SLE patients and reported that these patients have an almost 4-fold increased risk of developing lymphoma. However, the reasons for this are not known; the association may be due to the immune system over-activity of SLE itself, the medications used in its treatment, genetic/ environmental factors, or viral infections. Our current application defines an innovative research plan to assess the effect of SLE disease activity on lymphoma development, through a review of lymphoma cases arising in SLE patients. First, we will enlarge our previous cohort so that more cases of lymphoma can be identified. Then, for each lymphoma case identified in our international SLE cohort, controls without cancer will be selected from the cohort. Lupus disease activity will then be compared between cases and controls to determine if patients with higher disease activity are more likely to develop lymphoma. Additionally, by comparing the clinical and pathological features of these lymphomas developing in SLE to those in the general population, we will learn more about the role of SLE activity in increasing cancer risk. Our proposed project will help identify patients at highest risk for lymphoma and provide guidance regarding initiation and maintenance of therapy to control SLE. [unreadable] [unreadable] [unreadable]